SPH10 - Four-way Intercom

You can have four-way conference intercom with three other SPH10 users by adding one more intercom participant to the three-way intercom. While you are having three-way intercom, a new participant (D), who is an intercom friend of your intercom friend (C), may join the conference intercom by making an intercom call to your intercom friend (C). Please note that in this case, the new participant (D) is an intercom friend of (C), not of you (A).